Cisco Cisco IOS Software Release 12.0(22)S

This document describes the BGP Soft Reset Enhancement feature in Cisco IOS Release 12.0(22)S and 
includes the following sections:

The BGP Soft Reset Enhancement feature provides automatic support for dynamic soft reset of inbound BGP 
routing table updates that are not dependent upon stored routing table update information. This method 
requires no preconfiguration (as with the 

 command) and requires much less 

memory than the previous soft reset method for inbound routing table updates. 

Configurable routing policies for a peer, including route-maps, distribute-lists, prefix-lists, and 
filter-lists, may impact inbound or outbound routing table updates. Whenever there is a change in the 
routing policy, the BGP session must be cleared or reset for the new policy to take effect. The two 
methods for resetting a BGP session are hard reset and soft reset. 

Clearing a BGP session using a hard reset invalidates the cache and results in a negative impact on the 
network performance when the information in the cache becomes unavailable. A hard reset is also 
disruptive because active BGP sessions are torn down. 

12.0(7)T

This feature was introduced. 

12.0(2)S

This feature was integrated into Cisco IOS Release 12.0(2)S.

12.0(22)S

Support for IPv6 and VPNv4 address family support was added.